Never, Never, Ever Put Comments in Reverse Chronological Order
No! Make it stop! You never, never, ever put comments in reverse chronological order as the default format on a blog. Never.
Why?
A blog is nothing more than repurposed forum software in which only one person is allowed to post topics and everyone else is allowed to post responses. (Usually. There are multi-author blogs but exclusivity of authorship is still part of the deal.)
A single blog post is like a forum topic. The original poster—in this case, the blog author—writes the topic. Just like a forum, if anyone cares to respond, they write a comment after the original post.
Once a person responds with a comment, the topic is no longer a monologue. It has become a conversation between and among the original author and anyone else who responds. Comments, just like face to face conversations, sometimes also take on a life of their own apart from the original topic, sprouting new threads of thought and conversation which may have only a tiny relationship to the original topic.
Now, imagine going to your favorite forum, clicking a link to a topic, and then being forced to click to page 6 of the responses and going backwards from there in order to begin understanding how the most recent response came to be and how it might possibly be related to the original post. Madness!
Because of this, the only natural way to display comments (in English, that is) for anyone reading the conversation for the first time is to display them in chronological order. Outside of clever methods of interface design, the simplest way to solve this is to write left to right and top to bottom. Even though it may not be linear in thought, a conversation is always linear in time.
A Case of Incorrect Form Following Function
The reason many people display comments in reverse chronological order is because they want to show what’s new at the top. The problem is twofold: they are trying to make the list of comments perform two functions and they are not solving the desired function with the best form.
The primary function of a list of comments is to facilitate a conversation. New comments come after old comments. Again, in English we write left to right and top to bottom. Always remember that: the primary function of a list of comments is to facilitate a conversation.
Reverse chronological comments, however, are trying to make a list of comments perform a secondary function, “Show me what’s new in this conversation.” The form they have chosen to solve this function is, “Display a chronological conversation in reverse chronological sequence.” While this solves the problem for exactly one case, the case in which a person has read every comment except the last one, this makes no sense at all for any other case.
Solutions
There are many ways to show people what’s new. Currently, the two most popular are RSS feeds for comments and email notification. There are also several third-party web services that track conversations in comments and attempt to display them intelligently. Another way would be to allow people to sort the list of comments based on time (with chronological order as the default).
While it’s true that some people display recent comments on the index page of a blog, this has an entirely different purpose. The purpose is to show what’s popular by showing what’s recent. In doing so, blog owners are hoping you’ll be intrigued by the latest comment, click the link to read the related post, and join the conversation. But there is absolutely no way you can understand the conversation by reading the most recent comment out of its context.
There is probably much more that could be said about this: the technical details, the usability issues, the lovely diagrams with lines and arrows showing page flow, but I’ll leave that to someone else. I’ve said my peace.
If I encounter reverse chronological comments on your blog, I’m not reading the comments. Sorry, it’s not worth my time.
